Mechanical Engineering Commons^™

Optimization And Evaluation Of A Proportional Derivative Controller For Planar Arm Movement, Kathleen M. Jagodnik, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

In most clinical applications of functional electrical stimulation (FES), the timing and amplitude of electrical stimuli have been controlled by open-loop pattern generators. The control of upper extremity reaching movements, however, will require feedback control to achieve the required precision. Here we present three controllers using proportional derivative (PD) feedback to stimulate six arm muscles, using two joint angle sensors. Controllers were first optimized and then evaluated on a computational arm model that includes musculoskeletal dynamics. Feedback gains were optimized by minimizing a weighted sum of position errors and muscle forces. Generalizability of the controllers was evaluated by performing movements …

Optimality Principles For Model-Based Prediction Of Human Gait, Marko Ackermann, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Although humans have a large repertoire of potential movements, gait patterns tend to be stereotypical and appear to be selected according to optimality principles such as minimal energy. When applied to dynamic musculoskeletal models such optimality principles might be used to predict how a patient's gait adapts to mechanical interventions such as prosthetic devices or surgery. In this paper we study the effects of different performance criteria on predicted gait patterns using a 2D musculoskeletal model. The associated optimal control problem for a family of different cost functions was solved utilizing the direct collocation method. It was found that fatigue-like …

Development Of Criteria For Lamina Emergent Mechanism Flexures With Specific Application To Metals, Devin Bradley Ferrell

Theses and Dissertations

This thesis introduces new revolute and torsional lamina emergent mechanism (LEM) flexure designs that are suited for use in metals. Previous LEM flexures have been designed for use in highly elastic materials, such as polymers. In extending LEM flexure designs to metals, a LEM flexure design criteria is also introduced. The LEM flexure criteria is based on relative performance between the LEM flexure and a performance datum which the LEM flexure must improve upon. This performance datum, or benchmark, is a section of lamina that is of the same overall length, width, and thickness as the LEM flexure. An analysis …

A Proposed Learner-Centered Mechatronics Engineering Instructional Program, Patrick N. Currier, Richard Goff, Janis Terpenny

Mechanical Engineering - Daytona Beach

This paper examines the need and requirements for a mechatronics degree program. The results of a survey of the few existing programs in this field are provided. Then, using a case study example for Virginia Tech, a proposed mechatronics curriculum based on a learner-centered paradigm is described. The curriculum combines existing courses in mechanical, electrical, and computer engineering with new, hands-on courses to provide students with a chance to practice and explore the subject matter in ways consistent with the demands of both industry and accreditation. This program, if implemented, could provide a university with a unique offering to attract …

Determination Of Material Emission Signatures By Ptr-Ms And Their Correlations With Odor Assessments By Human Subjects, Kwanghoon Han

Kwanghoon Han

The objectives of this study were to determine volatile organic compound (VOC) emission signatures of nine typical building materials by using proton transfer reaction-mass spectrometry (PTR-MS) and to explore the correlation between the PTR-MS measurements and the measurements of acceptability by human subjects. VOC emissions from each material were measured in a 50-l small-scale chamber. Chamber air was sampled by PTR-MS to determine emission signatures. Sorbent tube sampling and TD-GC/MS analysis were also performed to identify the major VOCs emitted and to compare the resulting data with the PTR-MS emission signatures. The data on the acceptability of air quality assessed …

Role Of Faculty In Promoting Lifelong Learning: Characterizing Classroom Environments, Susan M. Lord, John Chen, Katharyn E. K. Nottis, Candice Stefanou, Michael J. Prince, Jonathon Stolk

Mechanical Engineering

Calls for educational reform emphasize the need for student-centered learning approaches that foster lifelong learning. To be a lifelong learner includes characteristics consistent with those of self-directed learners, such as being curious, motivated, reflective, analytical, persistent, flexible, and independent. Educational research has shown that the building of these aptitudes involves a complex interplay among nearly every aspect of human development. Instructor support of students’ self-directed learning (SDL) development relies on understanding and balancing these factors in the classroom. Engineering educators play a critical role in influencing outcomes related to SDL through their design of courses that support students’ transitions from …

Shape And Pose Recovery Of Novel Objects Using Three Images From A Monocular Camera In An Eye-In-Hand Configuration, Steven C. Colbert

USF Tampa Graduate Theses and Dissertations

Knowing the shape and pose of objects of interest is critical information when planning robotic grasping and manipulation maneuvers. The ability to recover this information from objects for which the system has no prior knowledge is a valuable behavior for an autonomous or semiautonomous robot. This work develops and presents an algorithm for the shape and pose recovery of unknown objects using no a priori information. Using a monocular camera in an eye-in-hand configuration, three images of the object of interest are captured from three disparate viewing directions. Machine vision techniques are employed to process these images into silhouettes. The …

Multidisciplinary Engineering Systems 2nd And 3rd Year College-Wide Courses, Kevin Craig, Mark L. Nagurka

Mechanical Engineering Faculty Research and Publications

Undergraduate engineering education today is ineffective in preparing students for multidisciplinary system integration and optimization - exactly what is needed by companies to become innovative and gain a competitive advantage in this global economy. While there is some movement in engineering education to change that, this change is not easy, as it involves a cultural change from the silo approach to a holistic approach. The ABET-required senior capstone multidisciplinary design course too often becomes a design-build-test exercise with the emphasis on just getting something done. Students rarely break out of their disciplinary comfort zone and thus fail to experience true …

Classes That Click: Fast, Rich Feedback To Enhance Student Learning And Satisfaction, John C. Chen, Dexter C. Whittinghill, Jennifer A. Kadlowec

Mechanical Engineering

No abstract provided.

Optimisation Acoustique De Paroi Par Algorithme Génétique Et Influence De L’Habillage Par Une Couche Poreuse, Nicolas Dauchez, Olivier Doutres, Jean-Michel Genevaux, Jean-Christophe Le Roux

Olivier Doutres Ph.D.

L’amélioration du confort acoustique dans les habitacles passe en particulier par l’optimisation de la transparence acoustique de parois simple ou double au moyen de matériaux viscoélastiques et poreux. Une méthode d’optimisation de paroi basée sur un algorithme génétique couplé à un calcul par matrices de transfert est présentée. Cette technique permet une exploitation efficace des itérations précédentes sans coût de calcul supplémentaire. Les résultats obtenus pour une simple et une double paroi sont analysés. Dans un deuxième temps, l’influence d’un habillage poreux est présenté en fonction de la nature du squelette : mousse polymère ou fibreux. On montre, à l’aide …

Mesure Des Propriétés Mécaniques Des Matériaux Poreux À L’Aide D’Un Transducteur Électrodynamique Sans Fer, Nicolas Dauchez, Olivier Doutres, Jean-Michel Génevaux, Guy Lemarquand, Sylvain Mezil

Olivier Doutres Ph.D.

Un banc de mesure des propriétés mécaniques des matériaux poreux est présenté. Il permet d'étendre les méthodes quasistatiques basées sur la compression d'un échantillon vers les hautes fréquences. Les méthodes quasistatiques sont limitées en fréquence (< 100 Hz) parce qu'elles négligent les éléments inertiels et le couplage avec l'air ambiant. Dans la méthode présentée, l'échantillon est placé dans une cavité étanche pour limiter l'effet de l'air ambiant et ainsi permettre une meilleure estimation du facteur de perte. Un transducteur électrodynamique a été conçu spécifiquement pour permettre une excitation sur une large gamme de fréquence : les premiers modes de l'équipage mobile sont au dela de 5 kHz. De plus, son architecture sans fer et sans suspension viscoélastique permet de l'utiliser comme capteur par le biais de son impédance électrique. L'impédance mécanique de l'échantillon est obtenue en inversant le modèle électromécanique du transducteur et les propriétés viscoélastiques - module d'Young et facteur de perte - sont obtenues par recalage d'un modèle analytique utilisant la théorie de Biot-Allard. Les résultats sont présentés pour une mousse polymère à cellule ouvertes. Le calcul des incertitudes montre que la méthode permet une bonne estimation jusque 500 Hz et permet de définir les conditions d'extension de la plage de fréquence.

Influence Of Ni Nanoparticle On The Morphology And Growth Of Interfacial Intermetallic Compounds Between

A.S. Md Abdul Haseeb

TiO2 thin films were deposited on unheated and heated glass substrates at an elevated sputtering pressure of 3 Pa by radio frequency (RF) reactive magnetron sputtering. TiO2 films deposited at room temperature were annealed in air for 1 h at various temperatures ranging from 300 to 600 °C. The structural and optical properties of the thin films were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and ultraviolet-visible-near infrared (UV-VIS-NIR) spectrophotometry. XRD results show that as-grown and post-annealed TiO2 films have anatase crystal structure. Higher substrate and annealing temperatures result in a slight increase of crystallinity. TiO2 …

Mechatronic Tools For The Modeling And Design Of Servo Motor Actuated Belt Driven Motion Systems, Robert William Copsey

Master's Theses (2009 -)

Mechatronics is defined as the synergistic integration of physical systems, electronics, controls, and computers through the design process, from the very start of the design process, thus enabling complex decision making. This definition reveals the elements involved yet it eludes to the complexity and the constant balance of tradeoffs which are prevalent in the context of applying Mechatronics to a successful design process. This work pursues the use of various tools for the application of Mechatronics to the modeling and design of a servo motor driven motion system.

The use of Mechatronics is pervasive in and among today's highly integrated …

Fishing Catch And Catch Rate Assesment Of Mini Trawl, Trapnet And Setnet Fisheries, Muhammad Firdaus

Makara Journal of Technology

Fishing Catch and Catch Rate Assesment of Mini Trawl, Trapnet and Setnet Fisheries. This paper is aimed at assessing fishing catch and catch rate of the dragged gear on shrimp, trapnet, and setnet fisheries in Tarakan. The catch and effort data (number and species) and the fishing time of captured units were used in this qualitative analysis of fishing catch and catch rate to describe catch composition and catch rate from three catch fishery units in Tarakan. The result of the research shows that in the catching operation the dragged gear on shrimp has two main catch targets, which are …

Online Real-Time Water Quality Monitoring And Control System, Paul Duffy, Gerard Woods, James Walsh, Michael Kane

Conference Papers

No abstract provided.

Turbulent Flow Studies Of A Scaled Model Of A Large Mining Truck - Computations And Experiment, Wayne Randolph Sexton

Mechanical & Aerospace Engineering Theses & Dissertations

Modern mining operations are highly reliant on the amount of material that can be removed from the earth, transported to processing, and then processed. The companies that design and build mining dump trucks concentrate on improving the material payload capacity. Currently, the largest trucks are 400ton-class trucks. The design of these large mining dump trucks certainly does not stem from aerodynamics, but rather, from functionality and payload As a result, the shear size and asymmetric functional design creates interesting turbulent wakes on, around, and behind these trucks. This research focuses on the turbulent flow behind the truck. Computational Fluid Dynamic …

Experimental Investigation Of Flow And Heat Transfer Characteristics Of R -134a In Microchannels, Abdullahel Bari

Doctoral Dissertations

The purpose of this study was to investigate the flow and heat transfer characteristics of liquid refrigerant R-134a in rectangular microchannels. The research concentrated mostly upon single-phase experiments with limited investigation of boiling phenomenon in microchannels. Tests were performed using rectangular microchannels with hydraulic diameters ranging from 112 μm to 210 μm and aspect ratios varying approximately from 1.0 to 1.5. The Reynolds number in the experiments ranged from 1,200 to 13,000 although most data were collected in the transition and turbulent flow regimes.

The experimental data for friction factor measurement had a similar trend as predicted by macroscale theory …

Marine Current Energy Devices: Current Status And Possible Future Applications In Ireland, Fergal O'Rourke, Fergal Boyle, Anthony Reynolds

Articles

There is a growing demand for the use of renewable energy technologies to generate electricity due to concerns over climate change. The oceans provide a huge potential resource of energy. Energy extraction using marine current energy devices (MCEDs) offers a sustainable alternative to conventional sources and a predictable alternative to other renewable energy technologies. A MCED utilises the kinetic energy of the tides as opposed to the potential energy which is utilised by a tidal barrage. Over the past decade MCEDs have become an increasingly popular method of energy extraction. However, marine current energy technology is still not economically viable …

On The Effective Elastic Properties Of Macroscopically Isotropic Media Containing Randomly Dispersed Spherical Particles, D. Cojocaru, Anette M. Karlsson

Mechanical Engineering Faculty Publications

computational scheme for estimating the effective elastic properties of a particle reinforced matrix is investigated. The randomly distributed same-sized spherical particles are assumed to result in a composite material that is macroscopically isotropic. The scheme results in a computational efficient method to establish the correct bulk and shear moduli by representing the three-dimensional (3D) structure in a two-dimensional configuration. To this end, the statistically equivalent area fraction is defined in this work, which depends on two parameters: the particle volume fraction and the number of particles in the 3D volume element. We suggest that using the statistically equivalent area fraction,introduced …

Wave Energy Converter Performance Modeling And Cost Of Electricity Assessment, Dmitri Jarocki

Master's Theses

California is experiencing a rapid increase in interest for the potential of converting ocean waves into clean electricity. Numerous applications have been submitted for the permitting of such renewable energy projects; however the profitability, practicability, and survivability have yet to be proven. Wave energy conversion technology has steadily matured since its naissance in the 1970’s, several wave energy power installations currently exist, and numerous plans for commercial power plant are in the works on the shores of multiple continents. This study aims to assess the economic viability of two proposed commercial wave energy power plant projects on the Central California …